What was supposed to be an open-ended debate on immigration reform stalled on Tuesday when Democrats objected to the Republican's first amendment, which would punish so-called sanctuary cities.

Minority Leader Chuck Schumer, D-N.Y., blocked a request by Majority Leader Mitch McConnell, R-Ky., to start by debating the sanctuary city language. Without Schumer's consent, the debate cannot begin until either late tonight or tomorrow morning.

The amendment mirrors legislation written by Sen. Pat Toomey, R-Pa., that would withhold certain federal funds from jurisdictions that do not cooperate with federal immigration officials when it comes to illegal immigrants.

Schumer argued Tuesday that the Toomey bill has nothing to do with the legislation that the two parties hope to pass, which would provide protection for so-called Dreamers in exchange for border security money, changes to chain migration and an end to the visa lottery system.

"The proposal he just offered does not address the underlying issues of this debate, why we are here," Schumer said. "It doesn't address the Dreamers, nor does it address border security."

Republicans said Democrats were free to offer their own amendment, but Schumer said in addition to the amendment his side would offer, he wanted Republicans to take up the immigration reform bill that mirror's President Trump's framework to protect Dreamers in exchange for border security and immigration policy changes.

That bill has not yet been introduced in the Senate, Republicans said.

McConnell's said Democrats are free to offer their own amendments, and said in the meantime that the Toomey proposal addresses "one of the most glaring aspects of our broken immigration system." The Senate defeated a similar sanctuary city measure in 2016.

McConnell urged Democrats to yield back time so the amendment process can start, which hadn't happened as of early Tuesday afternoon.

Republicans have put a one-week time limit on debating immigration.

"If we are going to resolve these matters this week, we need to get moving," McConnell said.